The statements in this section merely provide background information related to the present disclosure. Accordingly, such statements are not intended to constitute an admission of prior art.
An electric motor includes electrically conductive windings and a structure or frame to support the windings and magnets, when employed. In operation, stray capacitance can be generated between adjacent wires and between wires and the structure. Such stray capacitances include a parallel resistance element consisting of insulative material and air. In operation, a motor causes a rotor element to rotate in response to electrical current switching caused by a motor controller, which leads to high frequency ringing in the common mode at each rising edge and each falling edge of the motor controller output. The motor controller system contains a small parallel resistance. The high frequency ringing has repeatable and measureable characteristics including frequency, magnitude and duration that are directly related to the system resistance and stray capacitance/parallel resistance both between adjacent wires and between wires and the structure.
A parasitic or stray capacitance develops in an electric circuit between circuit components due to their proximity. A magnitude of energy loss can be determined in relation to electric frequency. Proximate conductors are affected by each others' electric fields, with an electric power loss, i.e., parasitic loss, directly proportional to frequency of the current. Parasitic capacitance can cause objectionable high frequency ringing, reduce motor torque output and/or increase power consumption.